Transmission control apparatus for vehicles, such as passenger cars, are generally classified into two major types, automatic transmission control apparatus and manual transmission control apparatus. In the automatic transmission control apparatus, a gear change can be made during travel of the vehicle by a human driver only moving or shifting a shift lever linearly to set the shift lever in a designated position (“D” range). In the manual transmission control apparatus, where there is provided an H-shaped shift pattern comprising shift paths connecting a plurality of shift positions corresponding to various speed levels, a gear change can be made by the driver manually manipulating the transmission shift lever to move the lever along shift paths to an appropriate one of the shift positions. Clutch is kept in an OFF state while speed change operation is being performed via the manual transmission control apparatus during travel of the vehicle. Further, the conventionally-known vehicular transmission control include those where the above-mentioned two types of transmission control apparatus can be used selectively as well as in combination.
Japanese Patent Laid-Open Publication No. 2002-257222 is named here as disclosing a technique relevant to the present invention. Specifically, this publication discloses a structure for forestalling possible erroneous operation in a transmission shift device. When the shift lever is set, for example, in the drive (D) range of the automatic transmission control apparatus, this transmission shift device functions to disable shift operation via a control mechanism virtually creating a repulsive resistance even if the driver tries to move the shift lever from the drive (D) range to another range, such as an “N” or “R” range, as long as a detected vehicle velocity satisfies a particular condition. The transmission shift device thus arranged can prevent the driver from performing erroneous operation.
In the conventional vehicular manual transmission control apparatus, it has been necessary for the driver to move the shift lever from a given shift position, along the shift paths forming the H-shaped shift pattern, to another desired shift position. The shift paths forming the H-shaped shift pattern have a mechanical structure, and they are in the form of guide grooves to impart mechanical restrictions or limitations to shifting movement of the shift lever. In recent years, a new type of device has been proposed for use in the manual transmission control apparatus, which is arranged to vary the structure of the H-shaped shift pattern in a finished vehicle in accordance with a request of the driver. Specifically, the proposed device is constructed to provide the H-shaped shift pattern by generating and imparting a load, i.e. reactive force, to the shift lever via electric/electronic control means, rather than mechanically providing the H-shaped shift pattern that functions to guide movement of the shift lever to set the shift lever in a desired shift position.
In the case where the H-shaped shift pattern is virtually provided in the vehicular manual transmission control apparatus by the electric/electronic control means generating a load (reactive or restrictive force) as noted above, it is possible to produce various other loads through various control schemes and thereby further enhance the function of the manual transmission control apparatus.
The above-mentioned technique applied to the manual transmission control apparatus for virtually generating a load or reactive force via the electric/electronic control means so as to impart the driver, manipulating the shift lever, with a pseudo force acting on the driver's sense of touch is commonly known as the “haptic” technique. In effect, the “haptic” technique is one of various techniques for interfacing with computers and is intended to create an interactive relationship between a human and a machine through the sense of touch or feel.